1. Field of the Invention
The present invention relates to an electron-emitting device which emits a large amount of electrons and can obtain a stable emission current, an electron source using the electron-emitting device, and a method for manufacturing an image displaying apparatus.
2. Related Background Art
A surface conduction electron-emitting device has been conventionally known as an electron-emitting device for constituting a flat display. The basic configuration of the surface conduction electron-emitting device is one in which a pair of device electrodes and an electroconductive thin film connecting both the device electrodes to each other are formed on a substrate and an electron-emitting region is formed by performing an energization processing of the electroconductive thin film.
Japanese Patent Application Laid-Open No. 2000-231872 discloses a configuration in which a film including carbon or a carbon compound as the principal component thereof is deposited on an electroconductive thin film at the circumference of the electron-emitting region in the electron-emitting device having the basic configuration described above in order to improve the electron emission efficiency of the electron-emitting device.
In the case where the surface conduction electron-emitting device is applied to a practical use, for example, a flat panel image displaying apparatus or the like, a demand of suppressing the power consumption thereof while securing the display quality thereof arises. According to the demand, increasing the electron emission efficiency of the device, i.e. a ratio of a current accompanying an electron emission (emission current Ie) to a current flowing through the device (device current If), is requested. In particular, in case of displaying an image having a high image quality, many pixels are accordingly needed, and it is necessary to arrange many electron-emitting devices correspondingly to respective pixels. For this reason, not only the power consumption of the whole device becomes large, but also the ratio of the area which wiring occupies on a substrate becomes large, which serves as restrictions on the designing of an apparatus. If the electron emission efficiency of each electron-emitting device is raised and the power consumption thereof can be suppressed in this case, the width of a wire can be made to be small to result the expansion of the degree of freedom of designing.
Moreover, not only the improvement of the electron emission efficiency, but also the improvement of the emission current Ie itself are still requested for the purpose of obtaining a brighter image or the like.
Furthermore, it is important without saying that the characteristics of the electron-emitting device is kept in a good state for a long time on the occasion of a practical use, and the suppression of the deterioration of the characteristics is successively requested.